Results from a preclinical study in rodents and a Phase 1/2, randomized, double-blind, placebo-controlled, parallel-group study of COVID-19 vaccine S-268019-a in Japanese adults

Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved..

BACKGROUND: In early 2020, developing vaccines was an urgent need for preventing COVID-19 from a contingency perspective.

METHODS: S-268019-a is a recombinant protein-based vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), comprising a modified recombinant spike protein antigen adjuvanted with agatolimod sodium, a Toll-like receptor-9 agonist. In the preclinical phase, it was administered intramuscularly twice at a 2-week interval in 7-week-old mice. Immunogenicity was assessed, and the mice were challenged intranasally with mouse-adapted SARS-CoV-2 at 2 and 8 weeks, respectively, after the second immunization. After confirming the preclinical effect, a Phase 1/2, randomized, parallel-group clinical study was conducted in healthy adults (aged 20-64 years). All participants received 2 intramuscular injections at various combinations of the antigen and the adjuvant (S-910823/agatolimod sodium, in μg: 12.5/250, 25/250, 50/250, 25/500, 50/500, 100/500, 10/500, 100/100, 200/1000) or placebo (saline) in an equivalent volume at a 3-week interval and were followed up until Day 50 in this interim analysis.

RESULTS: In the preclinical studies, S-268019-a was safe and elicited robust immunoglobulin G (IgG) and neutralizing antibody responses in mice. When challenged with SARS-CoV-2, all S-268019-a-treated mice survived and maintained weight until 10 days, whereas all placebo- or adjuvant-treated (without antigen) mice died within 6 days. In the Phase 1/2 trial, although S-268019-a was well tolerated in adult participants, was safe up to Day 50, and elicited robust anti-spike protein IgG antibodies, it did not elicit sufficient neutralizing antibody levels.

CONCLUSIONS: The S-268019-a vaccine was not sufficiently immunogenic in Japanese adults despite robust immunogenicity and efficacy in mice. Our results exemplify the innate challenges in translating preclinical data in animals to clinical trials, and highlight the need for continued research to overcome such barriers. (jRCT2051200092).

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:41

Enthalten in:

Vaccine - 41(2023), 11 vom: 10. März, Seite 1834-1847

Sprache:

Englisch

Beteiligte Personen:

Sonoyama, Takuhiro [VerfasserIn]
Iwata, Satoshi [VerfasserIn]
Shinkai, Masaharu [VerfasserIn]
Iwata-Yoshikawa, Naoko [VerfasserIn]
Shiwa-Sudo, Nozomi [VerfasserIn]
Hemmi, Takuya [VerfasserIn]
Ainai, Akira [VerfasserIn]
Nagata, Noriyo [VerfasserIn]
Matsunaga, Nobuaki [VerfasserIn]
Tada, Yukio [VerfasserIn]
Homma, Tomoyuki [VerfasserIn]
Omoto, Shinya [VerfasserIn]
Yokokawa Shibata, Risa [VerfasserIn]
Igarashi, Kenji [VerfasserIn]
Suzuki, Tadaki [VerfasserIn]
Hasegawa, Hideki [VerfasserIn]
Ariyasu, Mari [VerfasserIn]

Links:

Volltext

Themen:

9NEZ333N27
Adjuvants, Immunologic
Antibodies, Neutralizing
Antibodies, Viral
COVID-19 Vaccines
COVID-19 vaccine
Clinical Trial, Phase I
Clinical Trial, Phase II
Clinical trial
Immunogenicity
Immunoglobulin G
Journal Article
Preclinical study
Randomized Controlled Trial
Recombinant spike protein
Research Support, Non-U.S. Gov't
Safety
Sodium
Vaccines, Synthetic

Anmerkungen:

Date Completed 06.03.2023

Date Revised 17.04.2023

published: Print-Electronic

JPRN: jRCT2051200092

Citation Status MEDLINE

doi:

10.1016/j.vaccine.2022.12.025

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM350840946